Infrared ("IR") heaters are used in equipment for treating substrates such as in the drying of paper. Particularly effective IR heaters are described in U.S. Pat. Nos. 4,722,681, 5,024,596; 4,589,843; 5,464,346; 4,224,018; 4,604,054; 4,654,000; 4,500,283; 4,443,185; 4,474,552; 4,416,618; 4,447,205 and 4,378,207 which are incorporated herein in their entirety for all purposes by reference thereto.
U.S. Pat. No. 4,722,681 describes a IR heater body having a plenum chamber divided by a baffle into an unbaffled upstream intake compartment and a baffled downstream intake compartment. The matrix permits a gaseous combustion mixture to pass through the matrix and as said mixture emerges, said mixture is burned to heat emerging surface to incandescene. A matrix is located at the downstream end of the downstream intake compartment. The matrix is disclosed as being made from ceramic fibers about one inch thick and is adhesively secured to the side walls of the IR heater body. The matrix is formed as a block wherein its side walls are perpendicular to its top and bottom walls. The matrix fits against the comparably shaped end portions of the side walls of the IR heater body.
Another particularly effective IR heater is described in U.S. Pat. No. 5,464,346. As shown and described therein, an infrared heater for treating substrates comprises a gas fired IR heater having a body with a plenum chamber divided by a baffle into an unbaffled upstream intake compartment and a baffled downstream intake compartment. A gas inlet communicates with the upstream intake compartment for supplying a fuel-gas mixture. A fiber matrix is located at the mount or discharge end of the downstream intake compartment. The burner body includes peripheral side walls having downstream end portions which surround the matrix. The end portions and the matrix are outwardly tapered in the discharge direction.
There has been a need to develop an improved IR heater with a more durable and highly emittance fiber matrix. There also has been a need to develop a IR heater that can reduce the flame displacement effect of air impingement and improve fuel efficiency. There further has been a need to develop an improved IR heater that would not need a screen. Additionally, there has been a need to develop a IR heater that would have a screen forced fit without the IR heater need of a fastening means such as screws. Also, there has been a need to develop an IR that would have a removable screen. Furthermore, there has been a need to develop a high emittance, non-metallic reverbatory screen that would help the IR heater to emit more energy over the same surface area. Therefore, the same IR energy output would require a lower emitter operating temperature which would reduce the pollution, and improve the efficiency.